The present invention relates to a header comprising a middle section disposed on a main frame and at least two side sections disposed adjacent to the middle section, a cutterbar extending substantially across the width of the header, and at least one conveyor device which conveys crop cut by the cutterbar laterally in the direction of the middle section.
Headers of this type are designed as so-called belt cutting units which comprise a middle section disposed on a main frame and at least two side sections disposed adjacent to the middle section. A cutterbar extending substantially across the width of the header cuts crop. The header conveys crop cut by the cutterbar laterally in the direction of the middle section by means of a conveyor device. The middle section comprises at least one endless conveyor belt which endlessly circulates transversely to the conveyance direction of the conveyor device and is guided around two rollers spaced apart from each other. The rollers are disposed between support elements extending in parallel to each other in the conveyance direction of the conveyor belt and are mounted between bearing points provided on each of the support elements.
Such headers are distinguished by a high degree of flexibility in the adaptation to a ground contour of an area to be worked. The conveyor belt of the middle section, which is guided around the rollers, is connected by means of a connector in order to form an endlessly circulating conveyor belt. The connector consists of two square tubes which clamp the two belt ends together by means of screws. The disadvantage of this connecting point is that the conveyor belt is stiffened, in the circumferential direction, across a large area. As a result, the belt run becomes choppy as soon as this area passes by the particular roller. In order to achieve a smoother belt run, the diameter of the rollers is selected to be larger. This is disadvantageous, however, when the smallest possible distance is to be achieved between the roller and the cutterbar in order to obtain the most compact design of the middle section possible. A small distance from the roller to the cutterbar assists the crop flow, specifically during the harvesting of short crops with low yield.
In addition, the connecting point comprising the two square tubes has yet another disadvantage. The connecting point interrupts the conveyor belt and forms a breaking point which tends to fatigue, and this often occurs before the lifetime of the conveyor belt has been reached. The presence of the connecting point is due to the structural configuration of the middle section which does not allow for the installation of a conveyor belt without a connecting point. This similarly applies for the disassembly and the subsequent service of the conveyor belt for maintenance and cleaning purposes. Frequently, the interior of the conveyor belt can be reached, in order to carry out maintenance or cleaning work, only by separating the connecting point.
EP 2 586 288 B1 describes a header of the type mentioned at the outset, which comprises side sections and a middle section. The middle section comprises a central conveyor which includes an endlessly circulating, endless conveyor belt which is guided around two rollers which are spaced apart from each other, are disposed on two support elements extending in parallel to the conveyance direction of the conveyor belt, and are mounted on bearing points provided on each of the support elements. A belt tensioning device is disposed between the conveyor belt, with the aid of which an opposing pushing force is applied to the two rollers. For assembly and disassembly, it is provided that the central conveyor is articulated, on one side, on a support element so as to be swivelable about a horizontal axis and, on the other side, is detachably disposed on the other support element, and therefore the central conveyor can be swiveled downward, in sections. The swivel path is dimensioned in such a way that, in this position of the central conveyor, the endless conveyor belt can be removed from the rollers in a direction extending in parallel to the rollers. In this embodiment of the central conveyor, it has proven disadvantageous that the accessibility is extremely limited, in particular in the inner area of the conveyor belt and in the area of the support element on which the central conveyor is swivelably articulated. In order to also be able to reach the areas of the support element, on which the central conveyor is swivelably articulated, for cleaning purposes, the conveyor belt must be removed and subsequently slid back on, which is time-consuming.